In accordance with a rapid spread of information relevant apparatuses and communication apparatuses such as a personal computer, a video camera and a portable telephone in recent years, the development of a battery to be used as a power source thereof has been emphasized. The development of a high-output and high-capacity battery for an electric automobile or a hybrid automobile has been advanced also in the automobile industry. A lithium battery has been presently noticed from the viewpoint of high energy density among various kinds of batteries.
Liquid electrolyte containing a flammable organic solvent is used for a presently commercialized lithium battery, so that the installation of a safety device for restraining temperature rise during a short circuit and the structure for preventing the short circuit are necessary therefor. On the contrary, a lithium battery, namely a battery all-solidified by replacing the liquid electrolyte with a solid electrolyte layer, is conceived to intend the simplification of the safety device and be excellent in production cost and productivity for the reason that the flammable organic solvent is not used in the battery.
In a lithium ion battery, in order to improve electron conductivity in an active material layer, a configuration known is to further include a conductive auxiliary material in addition to an active material. For example, Patent Literature 1 discloses a configuration of an anode active material layer, the configuration that includes, as an anode active material, at least one kind of a group consisting of a simple substance, an alloy, and a compound of a metal element, and a simple substance, an alloy, and a compound of a metalloid element, as well as a carbon material including oxygen of over 0.2 weight % as a conductive auxiliary material. Also, Patent Literature 1 discloses a technique to improve dispersibility of a carbon material to an anode active material layer by conducting an oxidization treatment to the carbon material. Also, for example, Patent Literature 2 discloses a technique to introduce a hydroxyl group, a carboxy group, and an ether bond to the surface of a conductive carbon by conducting a treatment such as a high oxidization treatment to the conductive carbon that is used as a conductive auxiliary material.